Why convert EFI to Carbs!?

[Wiglaf]

I wonder if you can retrofit carbs as a cheap way to get ITB's under EFI control.

[10Toes]

Individual throttle bodies > Single throttle body.

On an N/A engine; 6 bike carbs, or 3 Webers, Dellortos, Mikuni PHH etc will ALWAYS be better than a single throttle injection system.

Better how?

[OniKyan]

Individual throttle bodies > Single throttle body.

On an N/A engine; 6 bike carbs, or 3 Webers, Dellortos, Mikuni PHH etc will ALWAYS be better than a single throttle injection system.

[JasonC]

Redneck Logic>EFI

Since this has been brought up and people think that they are so smart (hence a post like yours). And the old school technology is simple and out of date. Can you tune a carb? If its redneck, then it must be easy?

[gstuning]

Here are some fun facts.

Reason (no resons, just the one) why a carb is better then FI.
Given the distance fuel travels in a carbed manifold it usually has more time to mix with air. This is the sole reason why a carb CAN make more power then port fuel injection at WOT. As it will cause an improved burn in the engine (atomisation)

The cons of carbs are as follows.

Generally a lack of intake manifold freedom in terms of design, placement and so on.

A carb must have a restriction to cause fuel to actually be transported to the engine (venturi). While a FI engine does not and can therefor run larger diameter intake system. Ultimately giving more peak airflow.

A fuel injected system with raised injectors giving equal mixing time as carbs would, would ultimately be a better solution then carbs. Straight ITB´s with raised injectors vs straight carbs.

Fuel injection can have any mixture at any point in the pedal/rpm area where a carb could not.

Timed injection can give better throttle response then any other solution. As exactly the right amount of fuel for the current cycle can be injected right after the exhaust valve is closed giving the peak performance at that time. Without wasting any fuel either.

Fuel can be altered for each cylinder given it´s actual airflow requirements in any fashion, while a carbed car would do this automatically as depression will vary for each cylinder you can not control when and how this is done.

Fuel injection can control desired engine braking behaviour,
torque reduction,
anti wheelie action,
antilag,
overrun,
idle rpm by road speed by engine load (lights, heater, whatever) by gear, by anything you can input as a signal to the ecu.
Launch control,
speed limiter (by gear, by road speed, by load, by whatever you want)
and the list just goes on and on.

Nobody should be slated for picking a carb though, as it can get you something like 80% as good as EFI could do (not talking about power, just drivability), which in almost all cases is plenty. Given that the carb has wot and low load + idle jetting possible then by spending some time you can jet it rather good and not suffer problems.

However in the grand scheme of things fuel injection is better on all accounts apart from not just requiring a wideband and some screwdrivers to tune it pretty decent.

[trackjunkie21]

Redneck Logic>EFI

[Beske]

1st) Thank you for replying to my post. 2nd) Thank you for including such a super sexy pic of twin carbs!

No problem :p
Although I think the M30 posted by BMC227 is way sexier!

[slammin.e28]

Thanky you so much for responding! I am really starting to love BMW guys! I get way more quality responses on BMW forums than VW ones.

This is r3v. We must be doing something wrong....

[previasc96]

Good response

You're being stupid, i bet you haven't got a clue about cars/motors.


To the OP,

Carbs are good only if you've got a wide range of jetting on hand and if you know what you're doing.

Here are some pics of my heavily modified M30 triple carb engine

Thanky you so much for responding! I am really starting to love BMW guys! I get way more quality responses on BMW forums than VW ones.

[previasc96]

Gear head porn!

Why? Why not!



Best thing I got for my car since I have it!

1st) Thank you for replying to my post. 2nd) Thank you for including such a super sexy pic of twin carbs!

[e30s50dan]

Fuel injection will always win.

Especially comparing the single throat per cylinder setups (apples to apples). A perfect example of this are PMO carbs for 911 Porsches. They are basically a a triple throat weber IDA with all the bugs/ compromises worked out of it. It is widely considered the the finest carb to put on a 911 engine. They are functional works of art.

A few years ago Richard (PMO) made a throttle body version of his carb. Its the same as the carb except it has injector bungs and no float bowls (basically).

Guess which one makes more and broader power? The ITB's !

I would love to have either setup, but if you put a paid for pair of both kits in front of me, i would probably be leaving with a set of carbs in my hands and a skip in my step.

this is what i had on my 2.5L high comp engine,and they were almost perfect out of the box..Richard made them about perfect..I had a mid stumble around 2500-3000k that ended up being the fuel pump....

...ahh those were the days! :D

[slammin.e28]

I am just here for the lulz and the videos. Hot damn, M20s sound good.

Not as good as M30s.....

;);)

[Wh33lhop]

I am just here for the lulz and the videos. Hot damn, M20s sound good.

[F34R]

Why not just do EFI and carbs all at once? make double the HP

[slammin.e28]

^slammin is so concerned about retaining his girlish figure for lambo that he is not thinking clearly.

Shit, yeah. I'mfuckinglosingit. :oops: